DISGRACE: Derric Borrero gave Great Adventure tix meant for students to his brother, who sold them on eBay, authorities said. (NY Post: Chad Rachman)

Educators at a Staten Island school turned a fun theme park for kids into a scheme park for themselves.

The assistant principals kept more than $20,000 worth of complimentary tickets to Great Adventure for themselves — and their friends and families — although they had been donated by the amusement park for students to use.

The brother of one administrator at IS 24 in New Springville even hocked dozens of the free tickets on eBay at $30 a pop — and boasted to an undercover buyer that he had access to plenty of tickets “every year,” according to a city schools investigation.

The tickets were valued at $64.19 each, but were marked “complimentary.”

City officials slapped two six-figure administrators with $25,000 fines for their roles in the heartless heist — including Assistant Principal Richard Gilberto, who accepted nearly 400 tickets on the students’ behalf and then unapologetically distributed them to colleagues.

Also fined was Assistant Principal Derric Borrero, who got 75 tickets — including eight for his family visiting from Puerto Rico and 25 for his brother, the online scalper, according to investigators.

“He should get arrested — it’s stealing,” a sixth-grader said of Borrero. “It’s wrong. I think it’s unfair he steals and we had to pay $65 a ticket.”

More than 1 in 3 students at the mammoth middle school — where enrollment tops 1,400 — came from high-poverty homes last year, according to Department of Education data.

Yet neither administrator saw anything wrong with what they had done.

Gilberto told investigators he was given the tickets by a Great Adventure representative while he was chaperoning eighth-graders on a June 2011 trip to the New Jersey theme park.

A spokeswoman for the park confirmed that as part of the school’s purchase of tickets each year, it’s rewarded with comps “intended for the students who purchased the original tickets.”

Without telling his principal about the roller-coaster bonanza, however, Gilberto handed the tickets out to faculty “as a reward for their service during the school year,” the investigative report said.

Borrero, who received about 75 tickets, said he gave some away to a friend’s Cub Scout troop and told investigators he “never thought” his brother would sell the ones he was given, the report said.

An employee at Great Adventure who somehow caught wind of Borrero’s brother’s online deals bought one of the tickets through eBay, and then matched the serial number to one of the freebies that the park had given away. The worker then tipped off city investigators.

Schools Chancellor Dennis Walcott called the penalties “one of, if not the largest fines issued against individuals in a conflict-of-interest case. I took this very seriously.”

A man who answered the door at Gilberto’s home, but would not identify himself, told The Post, “Now’s not a good time.”